Patched GNU Make 4.1 sources to add improved error reporting, tracing,
target listing, graph visualization, and profiling. It also
contains debugger. See the remake-3-82 branch for a patched GNU Make
3.82.

Tracing and Debugging

Although there's a full debugger here, most of the time I can get by
using no options since normal output is a little more verbose and detailed.
When that isn't enough, I use the --trace or -x option, e.g:

remake -x <other make options>

But if you want the full debugger, use --debugger or -X:

remake -X <other make options>

To enter the debugger from inside a Makefile, use the built-in function $(debugger). For example here is a Makefile:

all:
$(debugger 'arg not used')
echo Nothing here, move along

When GNU Make is inside the all target, it will make a call to the
debugger. The string after debugger is not used, but seems to be
needed to get parsing right.

Getting Makefile Information

If there is project that you want a list of "interesting" Makefile
targets, try:

remake --tasks

If the project has commented its Makefile using remake-friendly comments you may get output like this: